Cutting tool assembly having attached spray nozzle housing

ABSTRACT

A cutting tool assembly ( 10 ) includes a support block ( 12 ) and a replaceable spray nozzle housing that can be manually installed onto a support block positioned on a drum in the field. Wherein the support block includes a fluid passage communicating water from a water supply to a fluid passage within the spray nozzle housing. The spray nozzle housing is connected to the support block by welding. The weld joint between the spray nozzle housing and support block forms a liquid tight seal. The spray nozzle housing is oriented on the support block so that water spray from the spray nozzle outlet is directed toward the tip of the cutting tool.

TECHNICAL FIELD

The invention relates to a cutting tool assembly having a replaceablespray nozzle housing.

BACKGROUND ART

Cutting tool assemblies for such applications as mining or road millingtypically comprise a cutting tool, sometimes referred to as a cuttingpick, rotatably mounted within a support block. The support block inturn is mounted onto a drum, chain or other body, typically by welding,which in turn is driven by a suitable drive means. A number of suchsupport blocks carrying cutting tools are mounted onto said drum tocontinually mine and remove material such as coal, rock, concrete,asphalt or concrete. The material in the earth strata being mined orremoved by the cutting tool is pulverized by the cutting picks as eachtip is rotated about the drum or chain into contact with the earthstrata. The material being pulverized by the impact of the pick explodesin all directions. Some of the pulverized material collides against thesupport block and other cutting tool structure. The continual collisionof pulverized material against the support block during operation causesabrasion and wear of the support block and any other components mountedon or near the support block.

It is also known to equip a cutting tool assembly with a spray nozzlefor spraying fluid onto a cutting tool so as to reduce the potential forignition of gases encountered during cutting or mining activities, suchas coal mining. These spray nozzles mounted on cutting tool supportblocks are also beneficial in suppressing dust particles that otherwisewould be stirred up into the atmosphere during the operation of thecutting tool. U.S. Pat. No. 5,392,870, Chapham et al, and U.S. Pat. No.5,378,048, Parrott, both disclose a water spray nozzle. U.S. Pat. No.5,392,870, Chapham et al, and U.S. Pat. No. 5,378,048, Parrott, are bothincorporated by reference in their entirety into the instantspecification. The discharge nozzles in both Parrott and Chapham areformed in the support block. Damage to the discharge nozzle outlet caneither result in enlarging the opening or alternatively can plug theoutlet close. If the opening is enlarged then water flows out of thenozzle at a greater rate, wasting water and causing an undesirablepressure loss in the drum manifold water passages that supply otherspray nozzles. On the other hand a potential fire hazard/explosionarises if a discharge nozzle becomes plugged and dust particles arestirred up into the atmosphere during the operation of the cutting tool.

The support block maintains its usefulness in holding the cutting pickafter the discharge nozzle is damaged. Despite this the support blockand cutting tool assembly must be removed from the drum and a newsupport block with a new spray nozzle is attached to the drum. Supportblocks are expensive themselves and attaching a new one to a drum istime consuming and disruptive of the mining operation. Typically areplacement support block must be welded onto the drum or chain back atthe workshop with precision instruments and tools, significantlyhampering the efficiency of the mining operation.

Rothkegal's U.S. Pat. No. 4,978,173 discloses a cutting tool assemblyhaving a holder body and a separate replaceable nozzle housing that isreleasably secured by screws to the holder body. The screws on suchprior art designs are often loosened on account of the vibrations causedby high-speed rotation of the drum during operation. The nozzle housingsbecoming damaged and/or lost requiring the mining drum to be shutdownfor maintenance. In other instances the screws or bolt heads used tofasten the nozzle housing to the holder body become damaged precludingremoval of the screw or bolt and the nozzle housing.

Siebenhofer et al.'s U.S. Pat. No. 5,498,069 discloses a cutting toolassembly including a spray nozzle in a bore of the support blockadjacent to the cutting tool. When the support block is sufficientlyworn away, it can no longer house the nozzle. Additionally the waterpassages disposed in Siebenhofer et al.'s support block for providingwater to the nozzle are configured such that they cannot be drilled outonce the pick support box is welded to a drum. As a result, when thepassages become blocked, such as by calcium deposits, the cutting toolassembly is no longer useful for cutting operations that require afunctioning spray nozzle.

The spray nozzle housing is intended to spray water adjacent the cuttingtool during the useful life of the other structure of the support block.It would be advantageous to have a support block that can be easilyfixed by having a spray nozzle housing that is easily replaced. It wouldbe advantageous to have a support block with a spray nozzle wherein thespray nozzle can be manually fixed, with a leak-free joint, to thesupport block in the field.

DISCLOSURE OF THE INVENTION

It is an object of the invention to provide a new and improved cuttingtool assembly having a support block and a replaceable spray nozzlehousing mounted to the support block, wherein the spray nozzle housingis simple in design and relatively economical to manufacture.

In one illustrated embodiment of the invention, the cutting toolassembly comprises a support block having a first cylindrical bore forreceiving a cutting tool. The support block also has a replaceableunitary spray nozzle housing, the nozzle housing is generallycylindrical with a flat bottom surface for mounting onto the supportblock. The nozzle housing has a nozzle outlet formed in a generallycircular forward face of the nozzle housing. The spray nozzle housinghas a nozzle fluid passage therein for communicating fluid from theinlet in the bottom surface to the nozzle outlet.

The cutting tool assembly in the illustrated embodiment comprises asupport block having first and second outer surfaces and a block fluidpassage. The block fluid passage communicates fluid between the firstand second outer surface portions of the support block. The replaceablespray nozzle housing is attached to the support block so that the nozzlefluid passage is in fluid communication with the support block fluidpassage. The support block passage comprises of two passage portionsboth having straight-line axes.

Advantageously, with such straight-line block fluid passage portionconfigurations the support block fluid passage can be easilymanufactured. The straight-line passage portion configurations alsopermit ease in cleaning debris such as calcium from the block fluidpassages so as to ensure maximum fluid flow therethrough.

Still another object of the present invention is to provide a design formanufacturing wear reducing components, which are easy to manufacture,install, and which are cost effective for their intended purposes.

While one embodiment of the new and improved cutting tool assembly isillustrated and disclosed, such disclosure should not be construed tolimit the claims. It is anticipated that various modifications andalternative designs may be made without departing from the scope of theinvention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of a cutting tool assembly showing one embodimentof the invention including a support block, a replaceable spray nozzlehousing, a sleeve and a cutting tool.

FIG. 2 is a cross-sectional view of the support block of the cuttingtool assembly of FIG. 1 with the cutting tool and sleeve removed takenalong lines 2-2 shown in FIG. 1.

FIG. 3 is a cross-sectional view of the support block of FIG. 1 with thecutting tool and sleeve removed taken perpendicular to the view shown inFIG. 2 along lines 3-3 in FIG. 2.

FIG. 4 a is a side view of the replaceable spray nozzle housing.

FIG. 4 b is a bottom view of the replaceable spray nozzle housing.

FIG. 4 c is a front view of the replaceable spray nozzle housing.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 a cutting tool assembly 10 according to the invention for use inmining and cutting operations. The cutting tool assembly 10 includes asupport block 12, a replaceable spray nozzle housing 14 connected to thesupport block 12, a protective tool sleeve 16 that is also removablyconnected to the support block 12, and a cutting tool 18 disposed withinthe tool sleeve 16.

The support block 12 is adapted to be connected to a rotatable drum (notshown) in any suitable manner, such as by welding, so that the cuttingtool 18 may be driven into material sought to be removed or mined. Thesupport block 12 has an exterior that includes first and second outersurface portions 20 and 22, respectively. The first outer surfaceportion 20 remains exposed during use, while the second outer surfaceportion 22 is concealed when attached to the housing.

As shown in FIG. 3, the support block 12 includes a block fluidpassageway 26 having an upstream portion 24 and downstream portion 28.Both portions 24 and 28 are substantially straight; the upstream portionof the block fluid passageway 24 has an inlet opening 25 in the secondouter surface 22 where the upstream portion 24 of the passagewayintersects the second outer surface. The downstream portion 28intersects with the first outer surface, where the downstream portion 28intersects the outer surface portion it forms an outlet opening 27. Theupstream portion 24 intersects the downstream portion 28 at sidewallchamber 23. The sidewall chamber 23 is manufactured by drilling a holeinto a sidewall of the first outer surface portion 20. The downstreamportion 28 and upstream portion 24 of the block fluid passageway arethen manufactured by drilling a hole from the sidewall chamber 23 tosecond outer surface 22 and the first outer surface 24 respectively.Next a plug 21 is inserted into the drilled out section of the sidewalland fixed thereto in a liquid tight fashion by any fastening means wellknown in the art. The upstream portion and downstream portion can becleaned of debris without removing the support block from the drum. Theplug is first removed during maintenance and next a drill is insertedinto both the upstream portion and the downstream portion to clean outany debris, such as calcium deposits, that may be clogging the blockpassage.

The first outer surface of the support block in the illustratedembodiment includes an upper portion and lower portion, the supportblock 12 illustrated in the embodiment of the invention is generallycannon shaped having an upper barrel portion and lower base portion aswell-known in the art. It should be appreciated that the invention isnot limited to the illustrated embodiment and that it is contemplatedthat the support block alternatively could have other shapes andgeometries.

The spray nozzle housing 14, as shown in FIGS. 4 a-4 c, is generallycylindrical and has a central longitudinal axis. The spray nozzlehousing 14 has a flat bottom surface 30 oriented at an angle withrespect to the central longitudinal axis of the spray nozzle housing.The central axis of the spray nozzle housing is oriented so that thewater spray from the nozzle outlet 34 is projected in the direction ofthe cutting tool tip. In the embodiment shown in FIG. 4 a the angle thebottom surface of the spray nozzle makes with the central longitudinalaxis is about 5° degrees. In the alternative and depending upon thespecific application, the bottom surface may be oriented at an anglewithin a range of between about 4° degrees to about 6° degrees. In otherinstances the angle may be present in a range between about 2° degreesto about 20° degrees. The spray housing has a main fluid chamber 35 thatis in communication with a spray outlet 34. Fluid flows from a mainchamber inlet passage 38 into the main chamber 35, the inlet passage 38is in communication with an elongated fluid recess chamber 36. Theelongated recess chamber 36 is formed in the flat bottom surface 30 ofthe spray housing. The elongated recess forms an inlet that is in fluidcommutation with the outlet opening 27 of the support block fluidpassage.

The spray nozzle housing 14 is welded to the first outer surface 20; thecross-hatching shown in FIG. 1 represents the weld joint. The spraynozzle housing is assembled to the support block 20 by conventionalwelding methods as are well known in the art. The spray nozzle housingis oriented on the first outer surface 20 of the support block so as toplace the spray nozzle housing in fluid communication with the blockfluid passage 26 in the support block. The disclosed embodiment includesan elongated recess chamber 32 having an elongated open end inlet thatallows for ease in proper alignment of the spray nozzle housing 14 intoposition so that the outlet opening 27 on the top of the first outersurface 20 of the support block is placed in proper fluid communicationwith the spray nozzle housing fluid passage. The elongated recesschamber 32 in the bottom surface 30 of the spray nozzle housing allowsfor greater tolerance in positioning the spray nozzle housing 14 intoalignment with the support block outlet 27 as opposed to the precisealignment which would otherwise be necessary if the supply opening intothe spray nozzle housing 14 had a cross-sectional area of the outletopening 27. Although it is not critical for welding purposes that thecross-sectional area of the open end of the recess chamber 32 as bestshown in FIG. 4 b is at least twice the cross-sectional area of theoutlet opening 27 on the top of the support block, such a relationshipmakes it easier to adequately position the spray nozzle housing manuallyprior to welding. Applicant also contemplates that the cross-sectionalarea of the open end of the recess chamber 32 alternatively is at leastthree times the cross-sectional area of the block outlet 27 opening.Applicant further contemplates that the cross-sectional area of theoutlet opening is at least four times the cross-sectional area of theblock outlet opening. The elongated recess chamber 36 allows a welder tomanually replace spray nozzles in either the field or the workshop.

The shape and geometries of the spray nozzle housing and/or nozzleoutlet is not intended to be limited to the disclosed embodiment whereinthe spray nozzle housing is generally cylindrical. The applicantcontemplates different spray nozzle housings having different shapesand/or sizes that may vary in accordance with different applications,manufacturing costs and/or other considerations. It is contemplated thatthe spray nozzle housing and support block may have a plurality ofdifferent shapes and geometries so long as the cooperating contactsurfaces between the spray nozzle housing and first surface of thesupport block are adapted to form enough contact with each other or topermit the spray nozzle housing and support block to be securely weldedtogether in a leak-free manner. It should be appreciated that the firstouter surface 22 of the support block and the bottom surface 30 of thespray nozzle housing may be configured to have any cooperating shape orgeometry which are well known in the industry to form a suitable liquidtight seal therebetween. It is contemplated that in an alternativeembodiment that the bottom surface of the spray nozzle housing might notbe flat but may have for instance have a curvature corresponding to theradius of curvature of the barrel portion of the support block.

The support block and spray nozzle housing of the application are madefrom any heat treatable, weldable alloy steel, including SAE 4130,15B37,4140, 8720, 8740, 8637h or other well-known steels used in theconstruction/mining industries. In one embodiment the spray nozzlehousing is manufactured from heat treated 4140 steel and the supportblock is manufactured from heat-treated 8637h steel.

The spray nozzle housing can be applied to the steel alloy support blockby a metallic electro-welding electrode out in the field. During suchwelding operations the weld is applied to the spray nozzle housing so asto not overheat either the spray nozzle housing and/or support block.The size of the spray nozzle housing is relatively small in comparisonto the support block resulting in a greater rate of heat dissipationfrom the spray nozzle housing relative to the support block, suchcooling rate variation can cause thermal stress fractures in the weldjoint. Accordingly as well known in the art the weld joint is applied byinitially forming a liquid tight weld dam about the fluid connectionbetween the support block and spray nozzle housing. Weld is nextapplied, without overheating the joint, about the initial weld dam tofurther strengthen the joint. Throughout the welding process therelative temperature of the spray nozzle housing and support block arecontrolled as well known in the art so that thermal stress fractures donot occur.

In the prior art seal means such as O-ring seals were required in thesupport block to form a liquid tight passage between a liquid supplysource and a spray nozzle housing on the support block. See the sealrings on the protective sleeve in U.S. Pat. No. 4,678,238 to Emmerich.By welding the spray nozzle housing 14 onto the support block andwelding the plug 21 to the support block, no seal rings on the supportblock or protective sleeve are necessary, and the protective sleeve canbe designed solely for the purpose of reducing wear on the supportblock.

To assemble the cutting tool assembly 10, the support block 12 is weldedto a rotatable drum (not shown) so that the support block fluid passageis in fluid communication with a fluid supply passage (not shown) withinthe drum. The weld sufficiently seals the support block 12 to the drumin a liquid tight manner. The protection sleeve 16 is then inserted inthe barrel bore 11 of the support body. The cutting tool 18 is theninserted into the tool sleeve 16 and secured to the tool sleeve 16 inany suitable manner such as a retainer ring. Next, the spray nozzlehousing 14 is positioned so that the fluid recess chamber 36 is incommunication with the outlet opening 27 of the support block fluidpassage and then welded into position.

In operation of the cutting tool assembly 10, a supply manifold in thedrum communicates water to inlet 25. Inlet 25 communicates with theupstream portion 24 next into sidewall chamber 23 and then thedownstream portion 28 of the support block fluid passage. The waterexits the support block at the support block outlet opening 27, flowsinto the recess chamber 36 through the spray nozzle housing and existsthe spray nozzle outlet 34 and toward the tip of the cutting tool 18.The water from the spray nozzle outlet reduces the potential forignition of gases such as methane encountered during cutting or miningactivities. The water spray additionally suppresses dust during miningand also helps to lubricate the joint between the cutting tool andsleeve for better rotation of the cutting tool.

While an embodiment of the invention has been illustrated and described,it is not intended that this embodiment illustrates and describes allpossible forms of the invention. Rather, the words used in thespecification are words of description rather than limitation, and it isunderstood that various changes may be made without departing from thespirit and scope of the invention.

1. A cutting tool assembly comprising: a support block to be secured toa moving element of a mining machine, comprising: a protection sleevefixed into said support block; a replaceable spray nozzle housing weldedonto said support block; a block fluid passage located in said supportblock wherein said replaceable nozzle housing is in fluid communicationwith said block fluid passage.
 2. The cutting tool assembly according toclaim 1, wherein said block fluid passage has an upstream portion anddownstream portion.
 3. The cutting tool assembly according to claim 1,wherein the support block has a first outer surface and a second outersurface and the block passage communicates fluid between said firstouter surface and said second outer surface.
 4. The cutting toolassembly according to claim 3, wherein said replaceable nozzle housingis fixed to said first outer surface.
 5. The cutting tool assemblyaccording to claim 2, wherein said upstream portion and said downstreamportion are substantially straight so as to permit a drill to beinserted into said first fluid passage for cleaning.
 6. The cutting toolassembly according to claim 1, further comprising: a cutting tool, saidcutting tool extends through said protective sleeve.
 7. A block for acutting tool assembly, said block comprising: a support block to besecured to a moving element of a mining machine; and a spray nozzlehousing, wherein said spray nozzle housing is welded to said supportblock.
 8. The cutting tool assembly according to claim 7, wherein thesupport block has a first outer surface and a second outer surface,wherein a block fluid passage communicates fluid between an inlet in afirst outer surface and an outlet in a second outer surface.
 9. Thecutting tool assembly according to claim 8, wherein said block fluidpassage has an upstream portion and downstream portion.
 10. The cuttingtool assembly according to claim 9, wherein said upstream portion andsaid downstream portion are substantially straight so as to permit adrill to be inserted into said block fluid passage for cleaning.
 11. Thecutting tool assembly according to claim 8, wherein said spray housingnozzle includes a fluid passage open end in communication with thesupport block fluid outlet.
 12. The cutting tool assembly accordingclaim 11 wherein said open end has a cross-sectional area at least twiceas great as the cross-sectional area of the block outlet.
 13. Thecutting tool assembly according to claim 7 wherein said spray nozzlehousing has a bottom surface that cooperates together with a fist outersurface of the support block to form contact surfaces.
 14. A method ofmaking a cutting bit support block having a spray nozzle comprising thesteps of: providing a cutter bit support block with a block fluidpassage having an outlet opening wherein the support block is eithercast or cold-formed from a heat treatable weldable steel; providing aspray nozzle housing with a fluid passage having an open end; connectingthe spray nozzle housing to the support block.
 15. The method of claim14 wherein the support block has a block fluid passage with an inlet forconnection to a water supply and a support block outlet at the oppositeend of said block fluid passage; said spray nozzle housing having arecess chamber; wherein said connecting includes aligning an open end ofsaid recess chamber with said support block outlet.
 16. The method ofclaim 14 wherein said connecting comprises welding said spray housingnozzle to said support block.
 17. A generally cylindrical spray nozzlehousing comprising: a generally circular forward face having an outlet;and a bottom surface, wherein said bottom surface has an elongatedrecess chamber.
 18. The generally cylindrical spray nozzle housingaccording to claim 17 wherein said bottom surface is generally flat. 19.The generally cylindrical spray nozzle housing according to claim 17,wherein said generally cylindrical spray nozzle has a centrallongitudinal axis, said generally flat bottom surface is oriented at anangle between from 2° to about 20°.